Can someome please answer a simple question:

If I write an article with say 2 key phrases inside which link to my website and then put that article on say 20 Article sites will google think its duplicate content?
I ask this because I wrote an article which I submitted to a high ranking blogg, which I would imagine did wonders for my SEO, however about 2 weeks later other websites had nicked it from this high ranking blog to post on their own blogg. They kept my links but would the power from the original blogg be lost because the article had been duplicated on a few other sites. If so should I be only putting an article on 1 article site only?

Thanks